Here the 1841 British edition, in anticipation of the following “their immortal souls” inserted the word immortal before the preceding souls. The resulting dittography is a clear redundancy and makes the following yea-phrase purely repetitive (“and land their immortal souls—yea their immortal souls—at the right hand of God”). The subsequent LDS edition (1849) removed the intrusive immortal. The critical text will maintain the original (and current) reading.
Summary: Maintain in Helaman 3:30 the lack of immortal before souls in the phrase prior to the yea-phrase; otherwise, the yea-phrase serves no purpose.